中文摘要：

通过测量不同La2O3含量的ZnLa2xNb2（1-x）O（6-2x）微波介质陶瓷的介电常数、符合正电子湮没辐射多普勒展宽谱和寿命谱,研究不同La2O3含量对该陶瓷介电常数和微观缺陷的影响。结果表明,x〈0.20时,随着La2O3含量增加,样品正电子平均寿命τm和缺陷浓度减小,致密度、商谱谱峰和介电常数εr升高。x=0.20时,样品正电子平均寿命τm和缺陷浓度最小,致密度、商谱谱峰和介电常数εr最高。x≥0.30时,样品正电子平均寿命τm和缺陷浓度升高,致密度、商谱谱峰和介电常数εr降低。

英文摘要：

The dielectric constant and micro-defect information of the ZnLa2xNb2（1-x）O（6-2x） microwave dielectric ceramics with different La2O3 content can be obtained by measuring the dielectric constant,positron lifetime and coincidence Doppler broadening spectra. The influence of La2O3 doping on the microdefects and dielectric constant of ZnNb2O6 has been studied. The experiment results show that for ZnLa2xNb2（1-x）O（6-2x） dielectric ceramics with low La2O3 content （x 0.20）,with the increase of La2O3 content,the mean positron lifetime τm and the concentration of defects decrease,while the density,the peak of the ration curve and the dielectric constant increase. The mean positron lifetime τm and the concentration of defects reach minimum values,while the density,the peak of the ration curve and the dielectric constant reach maximum values at x=0.20. For x≥0.30 sample,the mean positron lifetime τm and the concentration of defects increase,while the density,the peak of the ration curve and the dielectric constant decrease.